Thailand has a strict lese majeste law against insulting the monarchy that carries a penalty of three to 15 years in prison.
His highly-venerated father, King Bhumibol Adulyadej, died on October 13 at the age of 88 after an illness.
The government plans to take legal action against the Thai team of British Broadcasting Corporation (BBC) for its recent online report on the profile of His Majesty King Maha Vajiralongkorn Bodindradebayavarangkun.
"The authorities have to pursue the matter".
Deputy Prime Minister and Defense Minister Prawit Wongsuwan made the same point.
Since the article's publication, BBC's office in Thailand has received multiple visits from the Thai army and police. Social media groups, such as the Facebook group "V for Thailand", have been vigorously criticising the BBC, and posted the BBC's Bangkok phone number on their Facebook page, encouraging their followers to call and harass people who work there. It continues to publish and broadcast on its website, but the link about the King Rama X has been blocked in Thailand.
When attempting to access the article in Thailand, a message appears from the ministry for digital economy and society, announcing that the website contains "inappropriate information".
Following the police raid, the offices were left...
Observers say the reappointment of Prem indicates the new king's reluctance to make political changes and his determination to maintain the late king's legacy to stablise the country and to keep everything normal.
"[If] a news agency has a branch in Thailand staffed with Thai reporters [and] if they violate Thai laws, they have to be prosecuted", he said.
BBC Thai staff members could find themselves in trouble if formal charges are brought - especially as Prime Minister Prayuth Chan-ocha emerged on Wednesday with a statement to the press, noting that no agent, foreign or domestic, will receive special treatment where Thai law is concerned.
In one of his first official acts, King Maha Vajiralongkorn Bodindradebayavarangkun has retired eight members of his father King Bhumibol Adulyadej's aging privy council and named his own 11-member advisory body.
The activist, who is a student, was later released on bail.
Critics of the lese majeste law, known as Article 112, say it is used to silence political dissidents.
The ruling junta, which took power in a military coup in 2014, positions itself as a defender of the monarchy and has sought to appease ultra-royalist factions by pursuing anyone deemed to have breached lèse-majesté.